From a survey of coworkers you find that 70% of 160 have already received this year's flu vaccine. An approximate 95% confidence interval is (0.629, 0.771). a) How would the confidence interval change if the sample size had been 2560 instead of 160? b) How would the confidence interval change if the confidence level had been 90% instead of 95%? c) How would the confidence interval change if the confidence level had been 99% instead of 95%? a) Select the correct choice below and fill in the answer box within your choice. O A. The new confidence interval would be narrower. The standard error would be divided by a factor of O B. The new confidence interval would be wider. The standard error would be multiplied by a factor of